The present invention relates generally to magnetic resonance imaging (MRI), and more particularly to a system and method for aligning a patient in an open magnet MRI.
In open magnet magnetic resonance imaging (MRI), it is critical to position a patient such that the specific area to be scanned is positioned centrally within the field-of-view (FOV) of the MRI device. This is so because such open magnet MRI devices are constructed with relatively low magnetic induction permanent magnets. Typically the FOV imaging area is no more than approximately 40 cm. In order to acquire a quality image from a limited FOV, it is desirable to have the desired patient scan area centrally located within the FOV.
In order to locate the desired scan area within the FOV, prior art devices have used an alignment light on the outer periphery of the MRI housing to align a patient before entering the MRI. In operation, the MRI operator turns on the alignment light and manually positions the patient such that the light is directed to the area that the MRI operator desires to acquire an MRI scan. An automated moveable patient table then automatically moves the patient into the open magnet MRI a given distance as defined by the position of the exterior alignment light to the center of the FOV. Once an initial scan is taken, and the MRI operator determines that the patient is not properly positioned from reviewing the initial scan, the patient is withdrawn from the MRI device and realigned using the exterior light and the MRI image as reference points.
Such realignment techniques are time consuming and are an annoyance to patients. Therefore, it would be desirable to have an interior alignment light to indicate the center of the FOV without having to withdraw the patient.